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    <meta charset="UTF-8" />
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    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
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  <body>
    <script>
      // 状态发生改变 回调就都会被调用
      let p = new Promise((res, rej) => {
        // res(6);
      });
      // 指定回调 - 1
      p.then((value) => {
        console.log(value);
      });

      // 指定回调 - 2
      p.then((value) => {
        alert(value);
      });
    </script>
  </body>
</html>
